The vast improvements of the medical imaging and localization technology over recent years has brought a challenge to physics and computer technology to extend the capabilities of computerized treatment planning and optimization. The current release is being validated for clinical use on both Macintosh and Windows NT platforms. Once validation is complete, the Windows NT version will become the standard clinical platform and the Macintosh platform will be discontinued. The NT version is based on the OpenGL graphics engine, which provides superior 3D image display and manipulation. A new interactive algorithm has been developed for image fusion. Although this is currently used with CT and MRI images, any image set can be fused. File/image import and export in RTOG format has been implemented for communication with Lawerence Livermore National Laboratory. Import and ecport in DICOM-RT format will be implemented in FY-2000 for communication with the Radiological Imaging Workstation Project in conjunction with CIT. Communication with LLNL permits a clinical research project using their PEREGRINE Monte Carlo dose calculation engine. This engine will also be used to validate the photon dose calculation methodology of the NIH-TPS. Also planned is the use of the TPS for stereotactic radiosurgery/radiotherapy (SRS/SRT) as well as Intensity Modullated Radiotherapy (IMRT). A separate program for brachytherapy which performs calculations using the AAPM TG-43 formalism. Modifications to the angular and radial dose functions have been made to permit treatment planning for intravascular brachytherapy. Research will continue, with possible commercial co-sponsorship.